Elena Casetta

Biological conservation has a long story, but what distinguishes Conservation Biology from previous conservation fields is its multidisciplinary scope and its character as a mission-oriented crisis discipline. These characteristics suggested the introduction of the metaphor of biological conservation as a sort of surgery. This paper is about the initial stages of such surgery. Firstly, some data about the so-called “Big Sixth”—the disease—will be presented together with some information about Conservation Biology—the surgeon. Then epistemic and epistemological difficulties in extinction assessment and conservation prioritization, and triage in particular, will be pointed out. It will be argued that, while data deficiency arising from empirical and practical constraints can in principle be overcome, a different order of difficulties stems from the competition among several species concepts. In this case, it will be suggested that the extent of complications is of such significance to require a thorough re-assessment of the very nature of the patients, i.e., outside the metaphor, of the concept of species.

Despite increasing communication, accelerating policy and management responses, and notwithstanding improving ecosystem assessment and endangered species knowledge, conserving biodiversity continues to be more a concern than an accomplished task. Why is it so? The overexploitation of natural resources by our species is a frequently recognised factor, while the short-term economic interests of governments and stakeholders typically clash with the burdens that implementing conservation actions imply. But this is not the whole story. A different perspective on the problem shall here be considered, by exploring the conceptual and practical challenges posed by conserving biodiversity.

In recent years, we have assisted to an impressive effort to identify and catalogue biodiversity at the microbial level across a wide range of environments, human bodies included (e.g., skin, oral cavity, intestines). This effort, fostered by the decreasing cost of DNA sequencing, highlighted not only the vast diversity at the microbial level but also the importance of cells’ social interactions, potentially leading to the emergence of novel diversity. In this contribution, we shall argue that entities other than species, and in particular multispecies biofilms, might play a crucial—and still underestimated—role in increasing biodiversity as well as in conserving it. In particular, after having discussed how microbial diversity impacts ecosystems (Sect. 9.1), we argue (Sect. 9.2) that multispecies biofilms may increase biodiversity at both the genetic and phenotypic level. In Sect. 9.3 we discuss the possibility that multispecies biofilms, both heterotrophic and autotrophic, are evolutionary individuals, i.e. units of selection. In the conclusion, we highlight a major limitation of the traditional species-based approach to biodiversity origination and conservation.